It's difficult to predict with absolute certainty whether your son will get Computer Science (CS) at BITS Pilani or other campuses with a score of 256 in BITSAT.

CS is one of the most sought-after branches at BITS, and the cutoff scores for admission can be very high.

Cutoff scores for CS can vary depending on several factors, including:

• The total number of test-takers that year
• The difficulty level of the BITSAT exam
• The number of seats available in CS across different BITS campuses
  
  While not a guarantee, looking at previous years' cutoff scores for CS at BITS Pilani and other campuses can give you a general idea of the competition level. Search online for resources like "[Institute name] BITSAT cutoff" replacing "[Institute name]" with "BITS Pilani" or other campuses your son is interested in.
  
  If CS isn't an option, BITS offers a variety of other excellent engineering branches across its campuses. Some popular options include:
  
  
• Electronics and Communication Engineering (ECE)
• Electrical and Electronics Engineering (EEE)
• Mechanical Engineering (ME)
• Chemical Engineering (ChemE)
• Civil Engineering (CE)
  
  
  https://www.careers360.com/exams/bitsat
  
  I hope it helps!